The invention relates to environment sensors, and more particularly, to assemblies for mounting the environment sensor to a substrate in a building.
There is a growing demand for environment sensors to manage the environment and energy consumption in buildings. Several classes of environment sensors serve this need including ambient light sensors, temperature sensors, power meters, motion sensors, and infrared sensors.
Environment sensors, such as infrared sensors, are often anchored to various types of mounting substrates including light fixture enclosures or ceiling tiles of a drop-down ceiling in a building. Light fixture enclosures are made of thin rigid materials (e.g., sheet metal, plastic) having a thickness of approximately 0.5-5 mm. In contrast, ceiling tiles are made of relatively thick, soft, low density materials (e.g., compressed fiber, fiberglass) having a thickness of approximately 10-40 mm.
Because of the variation in material properties of the sensor mounting substrates described above, it is difficult to securely and conveniently remove and install one type of sensor in a wide variety of types of mounting substrates, and what is more, to do so such that the visible end of the sensor does not excessively protrude or stand proud from the substrate surface. It is also challenging to do so without damaging the substrate during the replacement operation.
There are a number of commercially available sensor assemblies that address some but not all of the above challenges. For example, FIG. 1 shows a figure of one type of known presence sensor 10 (see model no. talis MFM360-6-1, manufactured by Grasslin Gmbh, St. Georgen, Germany). The sensor 10 is intended to be inserted into an opening in a drop-down ceiling. The sensor 10 includes a set of springs 12 which automatically unfold after being inserted into the opening in the ceiling. The spring arms 12 operate with the lip 14 to hold the sensor in the drop-down ceiling. The springs, however, can undesirably allow for some slip or rattle relative to the hole depending on the thickness of the substrate and the mechanical spring constant of the arms (spring force depends linearly with deflection). The spring force may damage the soft tile substrates. Additionally, the sensor 10 is not easy to replace from the front of the ceiling because the springs 12 continuously urge the sensor rearward into the ceiling substrate. Additionally, the sensor 10 usually has an integrated cable 16 which must be disconnected from a remote power box in the plenum (i.e., the empty space between the actual ceiling and the drop-down ceiling). Consequently, the technician must access the plenum in order to replace the presence sensor 10. This is undesirable.
Accordingly, an improved apparatus that overcomes the challenges described above is desired. An improved apparatus is desired that allows for easy replacement of a sensor from the front of the drop-down ceiling, that can be removed and installed in multiple types of ceiling substrates, that has a firm and secure locked configuration, that does not have slip relative to the hole, that does not require tools nor a qualified electrician, and that does not damage the mounting substrate during installation and removal of the sensor.